The lawsuit argues the Department of Administrative Services does not have the legal authority to maintain the list of 1,471 disqualified workers revealed by The Associated Press earlier this month. The state's practice of telling workers they are disqualified forever only if they reapply for state jobs is a violation of their due process rights under the Iowa Constitution, the suit contends.

"The purpose and effect of Defendants' illegal conduct has been to place individuals on blacklists without notice or explanation, without due process, without cause, and for all time," Des Moines attorneys Roxanne Conlin and Tom Duff wrote in the petition filed in Polk County District Court.

The attorneys represent three former employees who say they were placed on the list without their knowledge when they were fired for performance. They include a 24-year Department of Human Services employee who was fired last year after falling behind on his work following a death in the family, a 25-year Department of Natural Resources accountant who was fired for allegedly "making too many mistakes" and a treatment worker at the Iowa Veterans Home who was fired for missing an on-call shift.

The lawsuit seeks certification for a class that could include more than 1,000 workers. It would encompass those who weren't notified they were placed on the list and given a chance to challenge the decision; workers who were fired for illegal reasons such as discrimination and retaliation but placed on the list; current state workers who are erroneously on the list; and workers who resigned but were unfairly disqualified.

The lawsuit asks for an order to stop the state's current practice. Instead, the state should be required to develop procedures barring only those "who have been discharged for serious reasons which would prevent them from safely being re-employed." The lawsuit says the state should have to notify such employees of their ineligibility, the reason for it and their appeal rights. It seeks unspecified compensatory damages and attorneys' fees.

The lawsuit names as defendants Branstad; former DAS Director Mike Carroll; DAS human resources executive William West; and the state.

Carroll told lawmakers during testimony April 3 that no such list existed. Days later, DAS released a spreadsheet in response to a request by the AP with 975 names of merit system workers who were excluded from employment based on previous firings and resignations. Branstad fired Carroll for giving false information to lawmakers on another subject during the same hearing.

DAS spokesman Caleb Hunter has said the state technically does not have a list, but rather individual records of employees who are coded in a computer database as disqualified. He says the agency has the authority to do so under an administrative rule, adopted in 1987 and updated in 2012, that says DAS can exclude applicants who were "previously discharged" or "resigned in lieu of discharge for cause."

In 2009, two administrative law judges concluded DAS lacks the statutory or regulatory authority to disqualify workers forever and can consider excluding former workers only if they apply for another job in the 19,000-employee executive branch.

After those decisions, the state began telling workers they were in disqualified status only if they reapplied for state jobs, which could be many years later.

In 2011, an administrative law judge said the state's practice of disqualifying those workers every time they apply still amounted to "an open-ended prospective bar to any employment" that wasn't authorized.

The DAS maintains that its practices are legal.

Many workers first learned of their status earlier this month when news outlets published the list of 975 names. The state has withheld the names of roughly 500 other probationary and at-will workers who are also disqualified, contending their names are not public record because they did not have the right to appeal their firings.

Duff said the delay in notifying workers when they are disqualified "puts them at a terrible disadvantage" if they try to appeal years later, when witnesses and documents might not be available.

"Notice and the right to be heard are two very basic procedural rights that people have, particularly when it comes to something important like your job and your ability to work," he said.